New shuttle promoter-probe vectors forE. coli andStreptomycetes

Summary Two new shuttle promoter-probe vectors forE.coli andStreptomycetes were constructed. Plasmid vectors allow the cloning of promoter-carrying DNA fragments based on the resistance to neomycin and chloramphenicol both, inE.coli andStreptomycetes. Using these vectors several promoter regions active either inE.coli orS.lividans were identified from the actinophage DNA.     

Cardiotrophin-1 review

Background: Cardiotrophin-1 is newly discovered chemokin with a lot of functions. Aim of our work was to describe most important of them. Methods: systematically scan of available scientific resources. Results: Cardiotrophin-1 stimulates the proliferation of cardiomyocytes. Cardiotrophin-1 expression and plasma values are elevated in individuals with heart failure and have high diagnostic efficacy for the heart failure. Plasma values are also an independent prognostic factor. Preliminary findings suggest that the determination of plasma cardiotrophin-1 may be useful for the follow-up of hypertensive heart disease in routine clinical practice. Cardiotrophin-1 also plays an important cardioprotective effect on myocardial damage, is a potent regulator of signaling in adipocytes in vitro and in vivo and potentiates the elevation the acute-phase proteins. Cardiotrophin-1 may play also an important protective role in other organ systems (such as hematopoietic, neuronal, developmental). Conclusion: Cardiotrophin is a newly discovered chemokin with a lot of system effects and is stable in system circulation hence permitting its development in the routine clinical investigation.     

Improving performance of docking-based virtual screening by structural filtration

In the current study an innovative method of structural filtration of docked ligand poses is introduced and applied to improve the virtual screening results. The structural filter is defined by a protein-specific set of interactions that are a) structurally conserved in available structures of a particular protein with its bound ligands, and b) that can be viewed as playing the crucial role in protein-ligand binding. The concept was evaluated on a set of 10 diverse proteins, for which the corresponding structural filters were developed and applied to the results of virtual screening obtained with the Lead Finder software. The application of structural filtration resulted in a considerable improvement of the enrichment factor ranging from several folds to hundreds folds depending on the protein target. It appeared that the structural filtration had effectively repaired the deficiencies of the scoring functions that used to overestimate decoy binding, resulting into a considerably lower false positive rate. In addition, the structural filters were also effective in dealing with some deficiencies of the protein structure models that would lead to false negative predictions otherwise. The ability of structural filtration to recover relatively small but specifically bound molecules creates promises for the application of this technology in the fragment-based drug discovery.     

Bryologische Fragmente

Ohne Zusammenfassung     

Glycosylated equine prolactin and its carbohydrate moiety

Glycosylated equine prolactin (G-ePRL) and nonglycosylated ePRL were purified to homogeneity from side fractions obtained during isolation of LH/FSH from horse pituitaries. Both PRL forms were isolated together in high yield by the isolation procedure used for glycosylated porcine PRL/(G-pPRL) and pPRL, involving acetone extraction/precipitation, NaCl and isoelectric precipitation, and gel filtration. Purification of G-ePRL required additional Con A chromatography. The N-terminal amino acid sequencing for 32 cycles of G-ePRL and ePRL resulted in sequences identical to the known primary structure of ePRL. Based on MALDI mass spectrometry analysis and SDS-PAGE mobilities,G-ePRL and ePRL had estimated molecular weights of 25,000 and 23,000 Da, respectively. G-ePRL displayed only 60% of the immunoreactivity of ePRL in homologous radioimmunoassay. Using the Nb2 lymphoma cell bioassay, ePRL was found to have about l/30th the mitogenic activity of bovine PRL; G-ePRL was approximately l/10th as active as ePRL. Glycosylation of G-ePRL at Asn³¹ was confirmed by isolation and sequence analysis of an enzymatically derived G-ePRL glycopeptide spanning residues 29–37. Monosaccharide compositions of intact G-ePRL and this glycopeptide were very similar (Man₃, GlcNAc₂, GalNAc₁, Fuc_0.6, Gal_0.2, NeuAc_0.15) and resembled that of G-pPRL. The glycopeptide contained one sulfate residue as determined by ion chromatography after acid hydrolysis, indicating the presence of a sulfated monosaccharide. Comparative carbohydrate analysis of G-ePRL and other G-PRL preparations suggests that the functionally significant Asn³¹ carbohydrate unit is a fucosylated complex mono- and/or biantennary oligosaccharide terminating with a sulfated GalNAc residue and two or three Man residues.